The invention relates to a drive assembly for a four wheel drive vehicle, particularly to an assembly including both a distributor differential and an axle differential. The distributor differential is designed as a spur gear differential and distributes driving torque between the drive axle and a first viscous coupling, which is provided for at least partially eliminating the differential function of the distributor differential. The axle differential and a second associated viscous coupling are provided for at least partially eliminating the differential function of the distributor differential. Both differentials and first and second couplings are arranged in the region of one of the drive axles. The ring gear of the distributor differential is connected to the main drive of the motor vehicle. Also, the distributor differential planetary gear carrier is connected to the axle drive of the second drive axle and its sun gear is connected to the axle drive of the first drive axle. The first viscous coupling is arranged between the planetary gear carrier and the sun gear. The second viscous coupling is arranged between the differential gear carrier of the axle differential of the axle drive of the first drive axle and its output end directed towards a wheel of the first drive axle. The two viscous couplings are arranged coaxially relative to one another on one side adjoining the axle differential and coaxially relative to its output end in the form of a plug-in shaft. The viscous couplings each include inner plates and outer plates, an inner plate carrier and an outer plate carrier and an inner space defined between both by housing parts. The couplings are at least partially filled with a high viscosity medium, such as silicone oil.
In the case of four wheel drive motor vehicles it is known to associate the distributor differential for distributing the driving torque to the two drive axles with the propeller shaft. It is also known to associate the distributor differential with the front axle. However, this arrangement leads to space problems. As cost reductions are important in the case of mass produced motor vehicles, attempts are made to obtain as many vehicle variants as possible by using modular design solutions.